Gas injection method for uniformly processing a semiconductor substrate in a semiconductor substrate processing apparatus

Abstract

A method of uniformly processing an upper surface of a semiconductor substrate in a plasma processing apparatus including a showerhead including gas outlets in discrete sectors of a process exposed surface thereof comprises processing the upper surface of the semiconductor substrate by flowing gas through a first discrete sector of the showerhead while preventing gas from flowing through an adjacent discrete sector of the showerhead, and processing the upper surface of the semiconductor substrate by flowing gas through a second discrete sector of the showerhead while preventing gas from flowing through an adjacent discrete sector of the showerhead. The flow of gas through the first discrete sector and the second discrete sector of the showerhead is time averaged such that the upper surface of the semiconductor substrate is uniformly processed.

What is claimed is: 
     
         1 . A method of uniformly processing an upper surface of a semiconductor substrate in a semiconductor substrate processing apparatus including a showerhead including gas outlets in discrete sectors of a process exposed surface thereof; the method comprising:
 processing the upper surface of the semiconductor substrate by flowing gas through a first discrete sector of the showerhead while preventing gas from flowing through an adjacent discrete sector of the showerhead; and   processing the upper surface of the semiconductor substrate by flowing gas through a second discrete sector of the showerhead while preventing gas from flowing through an adjacent discrete sector of the showerhead;   wherein the flow of gas through the first discrete sector and the second discrete sector of the showerhead is time averaged such that the upper surface of the semiconductor substrate is uniformly processed.   
     
     
         2 . The method of  claim 1 , further comprising processing the upper surface of the semiconductor substrate by flowing gas through a third discrete sector of the showerhead while preventing gas from flowing through an adjacent discrete sector of the showerhead wherein the flow of gas through the first, second, and third discrete sectors is time averaged such that the upper surface of the semiconductor substrate is uniformly processed. 
     
     
         3 . The method of  claim 2 , further comprising processing the upper surface of the semiconductor substrate by flowing gas through a fourth discrete sector of the showerhead while preventing gas from flowing through an adjacent discrete sector of the showerhead wherein the flow of gas through the first, second, third, and fourth discrete sectors is time averaged such that the upper surface of the semiconductor substrate is uniformly processed. 
     
     
         4 . The method of  claim 3 , wherein:
 (a) each discrete sector has an inner zone and an outer zone, the method comprising independently controlling the flow rate of gas through the inner zone and the outer zone of each discrete sector during processing; or   (b) each discrete sector has an inner zone, an outer zone, and one or more middle zones therebetween, the method comprising independently controlling the flow rate of gas through the inner zone, the outer zone, and the one or more middle zones of each discrete sector during processing.   
     
     
         5 . The method of  claim 3 , wherein each discrete sector has an inner zone and an outer zone, and the flow of gas is intermittently blocked through either an inner zone or an outer zone of the first, second, third, or fourth discrete sectors through which gas is flowed during processing. 
     
     
         6 . The method of  claim 3 , wherein
 (a) the same gas at the same flow rate is intermittently supplied to the first, second, third, and fourth discrete sectors at the same flow rate; or   (b) the same gas at different flow rates is intermittently supplied to the first, second, third, and fourth discrete sectors at varying flow rates.   
     
     
         7 . The method of  claim 3 , comprising:
 (a) flowing gas through the first and second discrete sectors while preventing gas from flowing through the third and fourth discrete sectors;   (b) flowing gas through the second and third discrete sectors while preventing gas from flowing through the fourth and first discrete sectors;   (c) flowing gas through the third and fourth discrete sectors while preventing gas from flowing through the first and second discrete sectors; and   (d) flowing gas through the fourth and first discrete sectors while preventing gas from flowing through the second and third discrete sectors.   
     
     
         8 . The method of  claim 7 , and repeating steps (a)-(d). 
     
     
         9 . The method of  claim 3 , comprising:
 (a) flowing gas through the first discrete sector while preventing gas from flowing through the second, third, and fourth discrete sectors;   (b) flowing gas through the second discrete sector while preventing gas from flowing through the third, fourth, and first discrete sectors;   (c) flowing gas through the third discrete sector while preventing gas from flowing through the fourth, first, and second discrete sectors; and   (d) flowing gas through the fourth discrete sector while preventing gas from flowing through the first, second, and third discrete sectors.   
     
     
         10 . The method of  claim 9 , and repeating steps (a)-(d). 
     
     
         11 . The method of  claim 1 , wherein the showerhead is a showerhead electrode and the processing comprises plasma etching the upper surface of the semiconductor substrate. 
     
     
         12 . A non-transitory computer machine-readable medium comprising program instructions for control of a plasma processing apparatus according to the method of  claim 1 . 
     
     
         13 . A method of uniformly processing an upper surface of a semiconductor substrate in a semiconductor substrate processing apparatus including a showerhead including gas outlets in discrete sectors of a process exposed surface thereof; the method comprising:
 sequentially flowing gas through one or more of the discrete sectors while preventing the flow of gas through at least one other discrete sector wherein the gas flowed through the discrete sectors is time averaged such that the upper surface of the semiconductor substrate is uniformly processed.   
     
     
         14 . The method of  claim 13 , wherein the showerhead is a showerhead electrode and the processing comprises plasma etching the upper surface of the semiconductor substrate. 
     
     
         15 . The method of  claim 13 , wherein:
 (a) each discrete sector includes an inner zone and an outer zone, the method comprising independently controlling the flow rate of gas through the inner zone and the outer zone of each discrete sector during processing; or   (b) each discrete sector has an inner zone, an outer zone, and one or more middle zones therebetween, the method comprising independently controlling the flow rate of gas through the inner zone, the outer zone, and the one or more middle zones of each discrete sector during processing.   
     
     
         16 . The method of  claim 13 , wherein each discrete sector includes an inner zone and an outer zone, the method comprising intermittently blocking the flow of gas through either an inner zone or an outer zone of any discrete sector. 
     
     
         17 . The method of  claim 13 , wherein:
 (a) the gas is intermittently flowed through discrete sectors for equal lengths of time; or   (b) the gas is intermittently flowed through discrete sectors for unequal lengths of time.   
     
     
         18 . The method of  claim 13 , wherein
 (a) the gas is intermittently supplied through an inner zone of a first discrete sector and an outer zone of a second discrete sector which is adjacent to the first discrete sector;   (b) the same gas at the same flow rate is intermittently supplied through the discrete sectors; and/or   (c) the gas is sequentially flowed through different combinations of discrete sectors of the showerhead.   
     
     
         19 . The method of  claim 13 , wherein each discrete sector includes an inner zone and an outer zone, the method comprising intermittently blocking the flow of gas through an outer zone of a first discrete sector and an inner zone of a second discrete sector adjacent the first discrete sector. 
     
     
         20 . A non-transitory computer machine-readable medium comprising program instructions for control of a plasma processing apparatus according to the method of  claim 13 .